Nelson Bay Cave
Nelson Bay Cave, previously known as Wagenaar's Cave, is a coastal archaeological site in the Robberg Nature Reserve on the Robberg Peninsula in Plettenberg Bay, South Africa, about 250 km east of Cape Town. The cave is 18 meters wide and 35 meters deep, and the cave opening is 21 meters above mean sea level. The cave was amongst the first sites excavated in the southern Cape aimed at recording changes in terrestrial fauna caused by changes in climate and sea levels. It documents environmental changes during glacial and interglacial periods. Additionally, the cave is recognized for its Stone Age artifacts that show the transition from Middle Stone Age to Later Stone Age technologies. It has been regarded as a type-site of the Robberg Later Stone Age Industry.
Geological Background
The Nelson Bay Cave, including Hoffman's/Robberg Cave, Matjes River rock shelter located 14 km north of Keurboomstrand, and other smaller caves formed in the eroded cliffs of the Robberg Peninsula. Robberg Peninsula is 4 km long and is geologically composed of sandstones and quartzites of the Cape Supergroup. The peninsula's cliffs have erosional features caused by wave-cutting, differences in rock types, bedding, and other bedrock characteristics that have led to the formation of caves and notches. Nelson Bay Cave is located on the south-facing slope of the Robberg Peninsula in quartz-sandstone and quartzite deposits. The cave developed in a contact breccia found at the contact between Silurian Table Mountain Group quartzite and Cretaceous Robberg Formation of the Uitenhage Group quartzitic sandstone during a time when mean sea level was 14 – 20 meters. The cave is eroded at the contact where overlying rocks are river-mouth deposits of the Uitenhage Group. Table Mountain Group soils in this area are characterized as being sand, low in pH, and low in plant productivity. Soils that developed from the Uitenhage Group deposits are variable and range from sandy loams to clay loams. The geological conditions of the cave have allowed for the preservation of archaeological material.Excavation History
Initial excavations were carried out in 1964–1965 by Ray R. Inskeep, removing younger Later Stone Age deposits. The early excavations revealed evidence of pottery, sheep remains, human burials, stone tool artifacts, ochre fragments, and shell ornaments. Later excavations in the early 1970–1972 by Inskeep and Richard G. Klein exposed Middle Stone Age deposits and bedrock material, estimated to date to the late Marine Isotope Stage 5. R. R. Inskeep continued excavations at the site till 1979. The cave was unofficially named the ‘Wagenaar’s Cave’, and unpublished documents referred to it as such. The cave was later referred to as the Nelson Bay Cave based on the official name of the path leading up to the cave, the Nelson Bay.File:Profile of Nelson Bay Cave.jpg|thumb|450x450px|Cave wall showing the stratigraphic profile of Nelson Bay Cave from Middle Pleistocene till Holocene.
Stratigraphy
The cave's stratigraphy is divided into three main sediment layers: the lower bed, the intermediate bed, and the upper unit. The lower bed of the cave has MSA deposits that occur in sterile gray loam and iron-rich sediments. Above the sterile layer is a layer that mainly contains materials from the Robberg Industry. This is followed by LSA artifacts, including marine mammals and shell middens dated to the Holocene. These main sedimentary layers are then divided into smaller descriptive units. The bottom units are natural sediments and those include the basal loam, pale brown loam, black loam I, black loam II, black loam III, rubble horizon, gray loam I, gray loam II, yellow stony loam, and brown stony loam. Following these are sedimentary units mainly consisting of cultural material. These include the gray-brown shelly loam, crushed shell midden, brown soil below midden Jake, midden Jake, midden rice A and B, brown soil below middens Glen and Helgren, midden Helgren and Glen, brown soil below middens Ivan and Betsy, middens Ivan and Betsy, and grey ash above midden Ivan. On top of GAI lies the pit fill, which has a mixture of debris and cultural material, which is also mixed with loamy sand. Abbreviations of the sedimentary units appear in later research and the full names are described by Klein. Units from the basal unit till the pale brown loam are correlated to the interglacial and early glacial period; black loam I till the rubble horizon falls within the lower pleniglacial and inter-pleniglacial period; gray loam II till the BSBJ fall within upper pleniglacial and late glacial; and units from J till GAI fall within the Holocene.| Epoch | Unit | Archaeological finds | Stone Age | Age |
| Holocene | Pit fill | Graves, pottery, seals, tortoise shells,domestic fauna, spurge flower, wild peach, mountain matenus, and shell pendants. | Post-climax Wilton | 4.4 ka BP |
| Holocene | GAI | Graves, pottery, seals, tortoise shells,domestic fauna, spurge flower, wild peach, mountain matenus, and shell pendants. | Post-climax Wilton | 4.4 ka BP |
| Holocene | B/I | Backed tools and small convex scrappers. Perforated white mussel shells, bovids, shellfish, fish, dwarf eelgrass, sumac, persimmon, and graves. | Wilton | 9.2 ka BP |
| Holocene | BSBB/I | Backed tools and small convex scrappers. Perforated white mussel shells, bovids, shellfish, fish, dwarf eelgrass, sumac, persimmon, and graves. | Wilton | 9.2 ka BP |
| Holocene | H/G | Backed tools and small convex scrappers. Perforated white mussel shells, bovids, shellfish, fish, dwarf eelgrass, sumac, persimmon, and graves. | Wilton | 9.2 ka BP |
| Holocene | BSBH/G | Backed tools and small convex scrappers. Perforated white mussel shells, bovids, shellfish, fish, dwarf eelgrass, sumac, persimmon, and graves. | Wilton | 9.2 ka BP |
| Holocene | Ra | Backed tools and small convex scrappers. Perforated white mussel shells, bovids, shellfish, fish, dwarf eelgrass, sumac, persimmon, and graves. | Wilton | 9.2 ka BP |
| Holocene | Rb | Large quartzite scrappers, backed tools, grazing and browsing bovids, bone fish gorges, seals, and dolphins. | Albany | 12 ka BP |
| Holocene | J | Large quartzite scrappers, backed tools, grazing and browsing bovids, bone fish gorges, seals, and dolphins. | Albany | 12 ka BP |
| Pleistocene | BSJB | Large quartzite scrappers, backed tools, grazing and browsing bovids, bone fish gorges, seals, and dolphins. | Albany | 12 ka BP |
| Pleistocene | CS | Large quartzite scrappers, backed tools, grazing and browsing bovids, bone fish gorges, seals, and dolphins. | Albany | 12 ka BP |
| Pleistocene | GSL | Large quartzite scrappers, backed tools, grazing and browsing bovids, bone fish gorges, seals, and dolphins. | Albany | 12 ka BP |
| Pleistocene | BSL | Microbladelets, bladelet cores, small scrappers, large grazers, and extinct bovids, and ostrich. | Robberg | 23 ka BP |
| Pleistocene | YSL | Microbladelets, bladelet cores, small scrappers, large grazers, and extinct bovids, and ostrich. | Robberg | 23 ka BP |
| Pleistocene | YGL | Microbladelets, bladelet cores, small scrappers, large grazers, and extinct bovids, and ostrich. | Robberg | 23 ka BP |
| Pleistocene | GL II | Angular flakes and backed pieces. | Howiesons Poort | 40 ka |
| Pleistocene | GL I | Angular flakes and backed pieces. | Howiesons Poort | 40 ka |
| Pleistocene | Rubble Horizon | Angular flakes and backed pieces. | Howiesons Poort | 40 ka |
| Pleistocene | BL III | Flake blades and convergent flakes. | MSA | 125 ka |
| Pleistocene | BL II | Flake blades and convergent flakes. | MSA | 125 ka |
| Pleistocene | BL I | Flake blades and convergent flakes. | MSA | 125 ka |
| Pleistocene | PBL | Flake blades and convergent flakes. | MSA | 125 ka |
| Pleistocene | Basal Loam | Flake blades and convergent flakes. | MSA | 125 ka |